Waymo, the self-driving division of Google's parent company Alphabet, accused Uber on Monday of violating a court order to provide thousands of documents in the self-driving technology lawsuit between the two companies.

In a letter submitted to the judge, Waymo's legal team says Uber "willfully ignored" the court order to provide about 14,000 documents and other materials Waymo says its former employee, Anthony Levandowski, stole before leaving and starting his own self-driving company, Otto. Otto was later bought by Uber and Levandowski became the head of Uber's self-driving car projects.

Waymo claims Levandowski used the documents he stole to help develop key lidar technology for Uber's self-driving cars. Lidar is the sensor on self-driving cars that help the vehicle "see" its surroundings and avoid obstacles.

Waymo's letter notes that in a hearing last week, Uber's lawyers appeared to waiver a bit when asked if they'd be able to provide all the documentation the court requested for the case. Uber's lawyers made the argument that some of the material was in Levandowski's po session and could not be retrieved. The judge in the case then said Uber could force Levandowski to provide the documents or risk being fired, according to transcripts of the conversation.

The letter also says Uber only submitted about 900 files to the court and the files lacked extensions and metadata, meaning they had to be viewed with special software. Waymo claims in the letter that Uber did not use the proper search methods as it was looking for the files and did not review files that Levandowski personally owned. Uber gave the files to the court just before midnight on Friday.

Waymo asked for a response to these allegations a few times over the weekend, but has not gotten one yet, the letter says. The letter asks the court to compel Uber to produce the missing documents within 24 hours.

Waymo's letter makes an argument that Levandowski is an employee of Uber and that Uber as a corporation has no fifth amendment rights.

Uber did not have an immediate comment on the accusations in Waymo's letter, but said its legal team would submit a response in its own letter Monday evening. However, the letter was never submitted. An Uber spokesperson told Business Insider that the company's legal team did not file the letter after the court said Monday night it would like representatives from Waymo and Uber to meet with the judge to go over the issues in Waymo's letter. That meeting will take place on Wednesday.

You can read the full letter from Waymo's legal team here:

UPDATE: On April 5, two days after Waymo originally filed its letter, Uber's legal team responded. In short, Uber argues that it can't force Levandowski to provide documents he has posession of if those documents aren't stored on Uber's computers. Uber says it only provided documents stored on its own systems and even searched an employee's phone.

Uber's letter also its lawyers did try to confer with Waymo's legal team and address their concerns about the discovery documents.